Method of inlaying



`April16,19 46. mmm 2,398,382

METHOD OFINLAYING f original Filed lJana i1, 11940 4 sheets-sheet s Y ATTORNEY April 16, 1946.

fr. WAINMAN METHOD` OF' INLAYING 'original Filed Jan. 11; 1940 4 sheets-'sheet 4` APatented Apr. 16,1946

Thomas Wainman, Arlington, N. J., assigner to Plastic Inlays, Inc., `Jersey City, N. J., a corporation oi' New Jersey Original application January 11, 1940, Serial No.V 313,380. Divided and this application September 18, 1943, Serial No. 502,996. In Canada yDecember 30, 1940 Claims. -(Cl. dlr-35) The present invention relates to inlaying and more particularly to an improved method for inlaying metal inlays into articles and particularly articles molded from synthetic resin compounds and is hereiny disclosed as a division of my application Serial No. 313,380, nled January 11, 1940.

vPlastic products are supplanting both .metals and wood for various uses. For example, in cars., various parts are now made of plastics which were formerly made of wood or metal. The possibility has been considered oi molding the bodies of aeroplanes from plastics. With such extensive use the appearance otj molded parts has become commonplace. Eiorts have been made to improve the appearance by utilizing various colors of materials but that has its limitations as there are only a limited number of distinctive colors.' AInlaying offers unlimited designs with various -types and colors oi' metal. However,

the inlays securely in recesses so that there will be no danger of their coming out. This is comf` plicated by reason of the parts being subjected' during their use to varying temperatures and weather conditions. Fourth, the parts are used in large quantities and their cost must be kept at a minimum to insure their extensive use.

'I'he present invention aims to minimize or overcome the'above objections by providing a method for inlaying which reduces the cost of inlaying, permits greater tolerances in the recess dimensions of the articles to be inlaid, and securely ilxes the inlays in the recesses regardless of the plastic material used and achieves the result without chipping or breaking the articles.

An object of the present invention is to provide an improved method for inlaying articles, particularly articles molded from synthetic resin compounds.

Another object of the invention is to reduce 'the cost of inlaying molded articles.

Another object of the invention is to providev an improved method of inlaying recesses in molded articles varying a maximum amount dimensionally from a pre-determined standard.

Another object of the invention is to provide a method of forcing the inlay in position by successive steps securely to embed the edges of the inlay in the article.

A further object of the invention is to provide a method of inlaying wherein the edges of the inlay can be embedded yin hard materials such as articles molded from phenolic condensation products.

Other and further objects of the invention will be` obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specication, wherein Fig. l is a front elevational view of a machine illustrating one way of practicing the method;

Fig. 2 is a 'side elevational view, partly in section, oi the machine taken along the line 2--2 of Fig. l;

Fig. 3 is a sectional view of the machine along the line 3`3 of Fis. 1;

. Fig. 4 is a detailed sectional 4--4 of Fig. 3 illustrating one of the pressure view taken on line vmembers forcing-a metal inlay'into an recess in a molded article;

Fig. 5 is a sectional view along the line 5---5A of Fis. 4:

Fig. 6 is an exploded perspective view of an article and metal inlay adapted to be assembled by be understood of course that, for diilerent'types of inlays and for -diilerent shapes of articles to be inlaid, certain changes will be desirablein the machine, particularly in the work holders for holding the articles to be inlaid and the pressure members forwapplying pressure to the inlays.

Described grirally; 'the machine illustrating one method of practicing the invention comprises a press having a table adapted to be rotated intermittently under the press head, The

table carries a series of work holders for engaging and retaining the articles to be inlaid. The pressure head is reciprocated vertically by a suitable drive to force the metal inlays into the recesses in the articles and to embed the edges of r the` metal inlays into the articles to prevent accidental dislodgement. The pressure head em- -bodies a plurality of pressure members, herein illustrated as four, to engage a plurality of articles simultaneously, and completes a single article at each operation of the press. In this Way, the pressure is applied to the metal and the edges of the metal are embedded in the molded article in four stages. In addition, the pressure heads with the exception of the last one to engage the article are heated to a substantial temperature so that the metal inlays will in turn be heated, which in turn will heat locally the parts of the recess into which the edges are to be embedded to facilitate secure engagement of the inlay. The drive of the press is ysuch that the pressure head can be retained in effective position for a predetermined period which can be readily changed to obtain optimum results. The table supporting the work holders is rotated step by step to present the work to the pressure head. The operator has ample opportunity and space to remove the inlaid parts and to place in' the holders articles to be inlaid.

Referring more particularly to Fig. 6, there is, shown an exploded view of a handle I which may be molded of a synthetic resin compound, for example, Bakelite," Durez and other similar ma` terials. The handle has a recess 2 of a desired shape and depth to receive a metal inlay 4. The metal inlay is preferably curved slightly so that when pressure is applied to it, it spreads out to embed its edges in the side of the recess to securely fix it in place. Improved results may be obtained by utilizing a piece of base metal 5, for example, brass, in the bottom of the recess under the metal inlay 4. In this way, the edges of the metal inlay are guided outwardly against the sides of the recess and do not scrape or embed in the bottom of the recess. While the use of a base metal 5 is illustrated herein and preferred, it is to be understood that the present invention is applicable to inlaying generally with or without the utilization of the base metal 5.

Referring more particularly to Figs. 1 to 3, there is shown a base 'I forming a platform or other suitable support for a rotatable table 8 secured tothe base by a bolt 9 and resiliently retained against the support by a spring I0 which is adjustably held in position by nuts I I. The table 8 may be provided with any suitable work holders I2 for engaging and retaining the work holders or articles to be inlaid and for presentation to the pressure applying head. The work holders will vary depending upon the type of articles being inlaid. In the embodiment illustrated in Figs. l to 6, work holders I2 are shown for the oven door handles I illustrated in Fig. 6 and, as illustrated in the detailed sectional view of Figs. 4 and 5, may comprise a central supporting part I4 and end pins I5. 'I'he pins I5 fit into recesses in the handle and the central supporting part I4 supports the middle of the handle directly under the inlay recess where the pressure is applied in inlaying the article. The work holders I2 may be secured to the table 8 in any suitable manner, for example, by the screws or bolts I1. A pressure member 2l is illustrated in Figs. 4 and 5 in effective position, and will be described hereinafter. Likewise, the drive for intermittently rotating the table and accurately presenting the workholder to the pressure head will be described later.

The pressure head Il utilized herein preferably comprises a plurality of pressure members] 6, I9,

20 and 2|. Each of the pressure heads I6, I9 and 20 preferably includes heating means such as an electric heating coil 28 which will maintain the temperature of the inlay engaging surface in heated condition. Excellent results have been obtained with temperatures of about 400 degrees Fahrenheit, but higher or lower temperatures may be utilized if desired. The entire pressure head is mounted in guideways 22 for reciprocation in a vertical direction by means of a crank 32 on the crank shaft 24. The work holders on the table 8 are so positioned that an article is presented to each of the four heads and pressure and heat are applied to the first three articles and pressure alone to the fourth. The heat communicated from the pressure members to the vmetal inlay causes the inlay and the edges thereof to assume a temperature` approaching the temperature of the pressure members, which in turn locally heats the sides or other portions of the recess where |;he edges of the inlay are being embedded and thus softens the material to facilitate embedding the edges therein. It has been found that with molded articles, such as Bakelite, that heating the inlay and locally heating the part to be inlaid prevents chipping and cracking of the Bakelite and greatly facilitates the inlaying operation. With softer materials, the

heating may be dispensed with, but with certain types of materials, it is very desirable.

It will be noted that the pressure is applied in stages during the inlaying operation. The pressure member I 6 is first applied to the inlay and thereafter in succession the pressure members I9, 20 and 2|; As described above, the pressure members I6, I9 and 20 are heated to facilitate the embedding operation. If desired, these pressure members may be adjusted to apply greater pressure in each successive pressing operation. The pressure member 2| is not heated and is preferably cold in order to cool the inlay and cause it to assume the size that it normally has at atmospheric temperatures. The pressure applied will force the edges firmly into the sides of the recess and thus will fix it securely in position in its cold state. The contraction of the metal upon cooling, without this fourth operation, would cause the metal to loosen from the position fixed by the pressure member 20 and the tendency for it to become dislodged would be increased. The application of the cold pressure member eliminates loosening due to shrinkage by xing the inlay in place while at normal temperatures.

'I'he pressure head, as illustrated, may comprise a at plate 25 attached to the vertical reciprocating member 2l by the bolts I3. The pressure members are bolted to the plate 25 by means of the bolts 26 through the intermediation cf springs 33 which may be adjusted as desired and the springs may have the proper strength to apply any desired pressure in the successive applications of pressure. A suitable reinforcing ange 21 may be formed on the plate 25 if desired. The pressure members may be heated electrically through the wires leading Ainto the units 28.

The drive for and the operation of the pressure head will now be described, Extending upwardly from the base or support 'I is a casting 29 having bearings 3 0 at its upperv en d in which the crank shaft 24 is mounted. O ne end of the crank shaft has a fly wheeltlthereon which may be asoaesa driven by a suitable motor and belt (not shown). As the' ily wheel 3| rotates the crank shaft 24, the pressure head I8 is reciprocated vertically by means of the crank or eccentric 32 and the rod 34 secured thereto. The pressure head may be ad justed vertically by means of the nuts 35. 4Normal operation of the machine would cause the pressure head to engage the work for a short period during each revolution of the ily wheel 3|. In order to secure an extended pressing and heating operation, with the pressure members effective upon the inlays, a clutch 36 is provided and is adapted normally to stop the movement of the pressure head while in its lowest position. In other words, the power for driving the shaft 24 is disconnected from the shaft automatically by the clutch 36 when the head is in its lowest position. The opposite end of the clutch lever 36 is attached to the solenoid 31 of an electro-magnet 38. When the electro-magnet 38 is operated to release the clutch member 35, the shaft 24 is rotated and the pressure head is raised to its upper position and lowered again to its effective pressure position where the clutch 36 again automatically stops it. The electric circuit through con; ductors 48 and 4| and the magnet 38 is closed by ratchet, is mounted on the reciprocating member 88 and vis retained against the periphery of the turn table' by means .of a spring 18. As the reciprocating member 68 moves back and forth, the ratchet member 68 engages the'recesses in the periphery of the turn table to rotate the turn table step by step and to present the work thereon to the pressure heads.

To lock the table 8 accurately. in position. there is provided a member 12 having 4a projection 14 adapted to engage in the recesses 1| in the periphery of the table. The lever 12 has one of itsends pivoted at 15 and is held in eective position by means of the spring 18 forcing it against the periphery of the table. As the reciprocating table moving member 68 moves backward for` engaging in another recess 1I to move the table 8, a'prolection "ion the member- 88 a. switch 38 operated by a ratchet wheel 42. The

pins or projections 44 on the ratchet wheel engage and depress a pin 45 which operates the switch 88 and closes the electrical circuit through wires 48 and 4I and the magnet 38 to release the clutch 36.

The ratchet wheel 42 isrotated by a ratchet 46 mounted on a bell crank 41. A lever 48 is pivotally mounted on the frame by means of a bolt 48 with one end 58 connected to the bell crank 41 and the other end 5I connected to a, vertically movable rod 52 mounted in bearings 54. A roller 55 on the upper end of the rod I52 engages a cam 56 on the side of the shaft 24-adjacent the drive wheel 3| where itis not affected by thefclutch 36, and, therefore, rotates continuously with the fiy wheel 3|. Upon eachrotation of the ily wheel, 3 I, the ratchet cam 56 forces downwardly the vertical rod 52 and oscillates the ratchet lever 48 to operate the ratchet member 46. In this manner, the switch 33 may be operated once in every desired number of rotations of the drive wheel3I. Thus a pressure head may be retained in its downwardly effective position for any desired period of time depending upon the article being inlaid and time required to obtain the best results. A period of several seconds has been found to give good results. The pressure period may be varied by changing the pivot 'position of the lever 48 which operates the ratchet. Three apertures 51 are shown at the middle 0f the lever 48 and others might be added to give any desired degree of variation. The shorter the left side of the'lever, the shorter the periods of effective pressure and more rapid the operation of the clutch member 36.

A crank is provided on the end of the shaft 24 opposite the ily wheel 3| by means of a disc 59 and a connecting member 58 thereon. A rod 60 is atttached to the member 58 at 6| to drive the work supporting table 8. The lower end of the rod 68 has a rack 62 formed thereon which meshes with a gear 64 on shaft 65. Theopposite end of the shaft 65 has a gear 66 (Fig. 3) meshing with a horizontally mounted rack member 68. Thus rotation of the shaft 24 reciprocates the rod 68 and rack 62 which in turn oscillate the shaft 65 to reciprocate the rack member engages the free end ofthe lever 12 to unlock the table. As the member 88 moves in the opposite direction to rotate the table, the member` 12 is permitted to engage the periphery of the table through the intermediation of the spring 16 to lock the table in proper position when the projection 14 enters the respective recesses 1I on the periphery of the table. In this manner the table is advanced one station and locked in position for each operation of the pressure head.

In practicing the method, an operator places a stove handle I or any other article to be inlaid on the pins I5 of the work holders I2 and ber I8 which applies lieat and pressure to the inlay to fix it securely in the recess. The pressure members I9 and 28 in successive stages also apply heat and pressure to the inlay. The several pressure members give Va series of operations and effective pressure applications suiilcient to embed the edges of the metal inlay in the recess regardless of the type of molded material used. The ilnal operation isperformed by the pressure member 2| which is cold thereby cooling the inlay and causing it to shrink or contract to its normal size and at the same time forcing it firmly into the material. As described above, the pressure head I8 is normally retained in its lower effective position by means of the clutch 36 which is effective to disconnect the drive automatically when the pressure head is down. Continued rotation of the fly wheel 3| reciprocates vertically therod 52 by means of the cam 56, which in turn rotates the ratchet wheel 42 by means of the lever 48 connected at one endto rod 62 and at its other end to the bell crank 41 carrying the ratchet 46. The ratchet wheel 42 has pins 44 thereon which engage pin 45 to operate the switch 38 and close the electric circuit through the magnet 38 which releases the clutch 36-causing the machine to begin another cycle. The table 8 is through the intermediation of the ma so and 68. A pivoted member 68, somewhat like a rack 62 meshing with gear 84 on shaft 65. The gear 66 'on the opposite end of the shaft 65 meshes with the rack 61 to reciprocate the driving member 68 for the turn table 8. The pivote'd mem ber 68 on the reciprocating member 68 moves the turn table forward one station for' each reciprocation of the member 68. The turn table is lockedin position by the lever 12 operated through theintermediation of spring 18. The proiection 'l1 on the member 88 automatically engages the member 12 and unlocks the table during each backward stroke of the member 88.

As stated hereinbefore different shapes and types of articles may require special holders therefor. 'I'here is shown in Figs. '7 and 8 a holder for articles suchas knobs or buttons used on the dash boards of automobiles. Referring more particularly to these figures, there is shown the turn table 8 having indexing peripheral slots 'H to permit the drive and positioning of the table for presentati/on of articles to be inlaid as described with respect to the embodiment illustrated in Figs. 1 to 6. Secured to the top of the table in any suitable manner is a series of work holders 88 here shown cylindrical in shape with the upper ends thereof recessed at 8| .to receive and hold the buttons or knobs 82. to be inlaid. 'I'he upper side of the recess is shaped to ilt and hold securely in positionthe underside of the buttons as shown more particularly in Fig. 8. Any suitable type of inlay may be applied to the button. As here shown, the inlay 8| has a circular portion with bars extending across the lower half thereof. The table 8 is rotated as described above to present the buttons with the inlays in the recesses thereof to suitable pressure members (not prises applying pressure to a; metal inlay to embed t the edges thereof into the sides of a recess in the article being inlaid, simultaneously heating the metal inlay to facilitate embedding the edges thereof in the article and thereafter cooling said inlay and applying additional pressure thereto to prevent the contraction of the metal during cooling from affecting the security of the inlay.

4. The method of inlaying, which method comprises applying pressure to a metal inlay in successive stages to embed the edges into an article molded from phenolic condensation products,

Iincreasing the pressure applied in successive stages, heating the inlay during the initial stages shown in Figs. '7 and 8) such as pressure members I8, I9, 20 and 2|. The same operations may be followed as described with respect to Figs. 1 to 6 to secure the inlays in place.

The buttons are small and lend themselves to automatic 'removal and for this purpose a duct 85 extends centrally through the holders 80 and connects with a tube 88 which is attached to a rubber tube 81. When the buttons reach the delivery station, the tube 88 registers with the duct 85 and a blast of air is applied to blow the buttons 82 into the chute 88 from which they are dropped into a suitable receptacle. The shield 89 prevents the buttons from being blown out of the chute. If desired a cam operated knock-out pin may be used for removing buttons from the holders at the delivery station. The

operation of the mechanism shown in Figs. 7 and 8 is otherwise the same as described in detail with respect to Figs. 1 to 6.

It will be seen that the present invention provides a simple and effective method of inlaying. The metal inlay is applied in a series ofy stages and subjected for a period of time to both heat and pressure and is thereafter subjected to additional pressure and reduced to normal temperatures while pressure is being applied thereto.

' The duration of the periods of application of pressure maybe changed as desired. Hard brittle materials such as Bakelite may be inlaid by the present method and machine without breaking or chipping. Maximum speed is obtained without reducing unduly the period of heat and pressure desirable for obtaining the b'est inlaying results.

As various changes may be made in the form, construction and arrangement of. the parts herein and as other means may be utilized for performing the method without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. The method of inlaying, which method comprises applying pressure to an inlay to force it into engagement with an article, simultaneously to facilitate embedding the edges in the article and cooling the inlay during the application of pressure in the last stage, to prevent the inlay `from loosening as a result of contraction during cooling.

5. The method of inlaying. which method comprises applying pressure to a curved metal inlay in successive stages to atten the inlay and to embed the edges into the sides of a recess in an article molded from synthetic resin compounds, increasing the pressure applied in successive stages, heating the inlay during the initial stages to facilitate embedding the edges in the article and cooling the inlay during the application of pressure in the last stage, to prevent the inlay from loosening as a result of contraction during cooling.

6. The method of inlaying, which comprises inserting a metal inlay having a curved crosssection in the bottom of a recess, applying pressure to the inlay to flatten the curved crosssection and to embed the edges into the sides of the recess, heating the inlay to facilitate embedding the edges thereof into the sides of the recess, thereafter cooling the inlay and subjecting lt to further pressure to expand the inlay and thereby compensate for the contraction occasioned by cooling.

7. 'I'he method of inlaying, which comprises placing a metal base member in the bottom of a recess, inserting a metal inlay having a curved cross-section in the recess over` the base member, applying pressure to the inlay to atten the curved cross-section and to embed the edges into the sides of the recess, heating the inlay to facilitate embedding the edges thereof into the sides of the recess, thereafter cooling the inlay and subjecting it to further pressure to expand the inlay and thereby compensate for the contraction occasioned by cooling.

8. The method of inlaying, which comprises heating a dished inlay, applying pressure to the inlay to atten it and to embed the edges thereof in an article, cooling said inlay and applying pressure thereto to further flatten and expand the size thereof, thereby tocompensate for any shrinkage due to cooling.

9. The method of inlaying. which method com'- prises applying pressure to a dished heated inlay in a recess to iorce the edges thereof into the sides of the recess, and applying additional pressure to the inlay after it has cooled to increase the size thereof, thereby to compensate for the contraction of the inlay during cooling.

10. The method of inlaying, which method comprises heating an inlay having a raised portion adapted to be attened to increase the size i of the inlay, placing the heated inlay in a recess, --applying pressure to increase the size of the inlay and to force the heated edges into the sides of the recess, and applying pressure to atten the inlay further after it is cooled to further lincrease the size thereof and to compensate for the decreasein size occasioned by cooling.

THOMAS WAINMAN. 

